Nota Terkini

Tuesday, September 08, 2009

[Chemistry Form 4] Alkaline Aqueous

Hydroxides of sodium, potassium, magnesium and calcium are bases. Bases have many common features: they have a bitter taste, are slippery to the touch, change the colour of indicators, etc. Aqueous solutions of soluble bases are called alkalis.

Solution vs Ionisation
Some strong bases like calcium hydroxide aren't very soluble in water. That doesn't matter as what does dissolve is 100% ionised into calcium ions and hydroxide ions. Thus, calcium hydroxide still counts as a strong base because of that 100% ionisation.

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Hydroxide that are alkalis:
  • NaOH
  • Mg(OH)2
  • KOH
  • LiOH
  • NH4OH

The following the dissociation of acids and base.

Hydrochloric acid
Formula: HCl
Equation to show dissociation: HCL -> H+ + Cl-

Nitric acid
Formula: HNO3
Equation to show dissociation: HNO3 -> H+ + NO3-

Ethanoic acid
Formula: CH3COOH
Equation to show dissociation: CH3COOH -> CH3COO- + H+

Potassium hydroxide
Formula: KOH
Equation to show dissociation: KOH -> K+ + OH-

Sodium hydroxide
Formula: NaOH
Equation to show dissociation: NaOH -> Na+ + OH-

Calcium hydroxide
Formula: Ca(OH)2
Equation to show dissociation: Ca(OH)2 -> Ca2+ + 2OH-

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1 comment:

  1. Cikgu naza
    Semua perkara2 yg kait mengait ngn kimia..kita sedut. Teeemaaaa kasih manyak2.

    ReplyDelete